Ryoko Nishizuka, who designed the Ryo typeface families and Kazuraki, graduated from Musashino Art University in 1995, and began working at Morisawa & Company, a leading type foundry and manufacturer of digital typesetting systems in Japan. Next, she decided to work as graphic designer at a design studio. But her main interest was always in typeface design. In 1997, Ryoko joined Adobe. She has been involved in the development of the Kozuka Mincho and Gothic typefaces designed by Masahiko Kozuka.

In 1999, Ryoko received an honorable mention for her typeface "Branch Letter" at the Morisawa Awards International Typeface Design Competition. In 2002, her calligraphic typeface "Teika" won the Silver Prize at the same Morisawa competition, which was later expanded and refined to become Kazuraki, which is being heralded as the first fully-proportional OpenType Japanese font. In 2003, Ryoko created the Ryo Text and Ryo Display "kana" typeface families, followed by the Ryo Gothic family in 2004. The Ryo Text and Display families are composed of nine OpenType Japanese "kana" subset fonts covering eight different weights. The Ryo Gothic family consists of seven weights. The brightness emitted from the Ryo families is based on her original interpretation of traditional styles of "kana" calligraphy and type design. Kazuraki then consumed much of Ryoko's design effort, and was subsequently released for the first time in 2009. The special glyph set for Kazuraki including proportional glyphs and ligatures was expanded, and the font was updated in 2010.

In 2014, Ryoko directed the design work for Source Han Sans, Adobe's first Pan-CJK typeface family composed of seven weights. Each Source Han Sans font includes more than 65,000 glyphs to support the scripts used by Simplified Chinese, Traditional Chinese, Japanese, and Korean. Source Han Sans' moderately modern style makes text clearer and more readable on smaller devices such as tablets and smart phones.

Source Han Serif, the serif-style counterpart to Source Han Sans, was released in 2017. Like Source Han Sans, it is also optimized for screen display, but has a completely different personality that works well for more literary texts, and for graceful, stylish headings. It also works beautifully in print.